By Joshua McElwee
VATICAN CITY, May 25 (Reuters) - Catholic popes have been urging global leaders to address social justice issues for 135 years across some two dozen major documents that many of the world's 1.4-billion-faithful can cite by their two- or three-word titles.
"Rerum Novarum" from Leo XIII in 1891 called for better conditions for workers in the Industrial Revolution. "Pacem in Terris" from John XXIII in 1963 appealed for nuclear disarmament amid the Cold War. "Laudato Si'" from Francis
in 2015 pleaded for swift action to address climate change.
Leo XIV has now added his name to the pantheon, issuing a fervent manifesto on Monday titled "Magnifica Humanitas" (Magnificent Humanity), urging global governments to slow down the development of AI systems.
"Like other popes before him, Pope Leo is responding to one of the most pressing social issues of his time," John Thavis, a longtime Vatican correspondent who covered three papacies, told Reuters.
"Clearly (Leo) wants to help shape the debate over technology and AI, by emphasizing the moral and ethical arguments that centre the human person," said Thavis.
A year into his papacy, Leo formally signed the text about AI on May 15, the 135th anniversary of his predecessor's publishing of "Rerum Novarum", firmly tying the newest papal document urging world action on social issues to the papal text widely considered to have done that first.
POPES CHOOSE ENCYCLICAL TOPICS CAREFULLY
Anna Rowlands, a British academic and Church adviser, said at a Vatican event presenting Leo's text on Monday that for more than a century popes have cautioned that the world "will not be saved by the market."
"Today, Pope Leo cautions that we will not be 'saved' by AI," she said.
Encyclicals are one of the highest forms of teaching from a pontiff to the Church's members.
Popes choose the topics of encyclicals carefully to highlight the main priorities of their papacies, as the texts, which can span hundreds of pages, often take years to prepare.
The late Pope Francis, who led the Church for 12 years, authored only four of the documents.
Leo, who has adopted a more forceful tone in recent months and has drawn the ire of U.S. President Donald Trump after criticising the Iran war, warned in his text that AI spreads misinformation, prioritises conflict and could lead the world down a path of unending war.
At Monday's Vatican event he also expressed concern that some autonomous weapons systems have advanced "practically beyond any human reach to govern them".
MIXED RECORD OF SUCCESS FOR PAPAL ENCYCLICALS
Papal encyclicals urging action from world leaders have a mixed record of leading to substantive changes.
"Pacem in Terris", published just months after the 1962 Cuban missile crisis, is credited by some historians with giving moral backing to negotiations between then-U.S. President John F. Kennedy and Soviet leader Nikita Khrushchev that led to the Partial Nuclear Test Ban Treaty.
Francis, whose "Laudato Si'" was the first papal document to endorse the scientific consensus that greenhouse gases are warming the Earth's atmosphere, lamented frequently that governments were not doing more to mitigate climate change.
Thavis said it is usually hard at first to judge whether a papal encyclical will have lasting impact, as it takes time for the lengthy documents to be digested by people worldwide.
"Their ideas tend to surface gradually in the public square, in the media and in grassroots activism," he said. "I suspect this encyclical will act as a landmark reference point in the ongoing debate over artificial intelligence."
The document is already available to read on the Vatican website in a number of languages, and will also be distributed as a booklet for reading and discussion.
Chris Olah, a co-founder of Anthropic, one of the world's top AI companies, took part in the Vatican's event on Monday launching Leo's text and thanked the pope for addressing the problems raised by the disruptive, new technology.
He said firms like his faced strong commercial pressures and needed outside scrutiny.
Leo called in his text for robust international regulations to oversee AI development and for ownership of AI data not to be left solely in private hands.
(Reporting by Joshua McElweeEditing by Keith Weir)
